IBM DB2 11.1 Advanced DBA for Linux, UNIX, and Windows — Question 46

Which of the following isolation levels most reduces concurrency and is most likely to cause lock escalations?

Answer options

• A. Read Stability
• B. Cursor Stability
• C. Repeatable Read
• D. Uncommitted Read

Correct answer: C

Explanation

The Repeatable Read isolation level ensures that if a transaction reads a row, it can read that same row again without changes from other transactions, which can lead to increased locking and reduced concurrency. In contrast, Read Stability and Cursor Stability allow for more flexibility in reading data, and Uncommitted Read does not enforce locks at all, thus promoting higher concurrency.